Commit d23ca15a authored Nov 14, 2006 by Andrea Bittau Committed by David S. Miller Dec 02, 2006

[DCCP] ACKVEC: Optimization - Do not traverse records if none will be found



Do not traverse the list of ack vector records [proportional to window size]
when we know we will not find what we are looking for.  This is especially
useful because ack vectors are checked twice:
1) Upon parsing of options.
2) Upon notification of a new ack.

All of the work will occur during check #1.  Therefore, when check #2 is
performed, no new work will be done.  This is now "detected" and there is no
performance hit when doing #2.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

parent 09dbc389

net/dccp/ackvec.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -383,7 +383,8 @@ void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec av, struct sock sk,
		(unsigned long long)avr->dccpavr_ack_ackno);
		dccp_ackvec_throw_record(av, avr);
		break;
		}
		} else if (avr->dccpavr_ack_seqno > ackno)
		break; /* old news */
		}
		}